A problem which arises in an attempt to obtain a positive seal at the juncture of the transformer bushing and the connector relates to the means for locking the connector in place. Presently used lock nuts leave a portion of the transformer stud exposed. Eliminating the lock nut by threading a set screw directly to the threaded area of the transformer stud is impractical. Thread damage which would be imposed on the transformer stud makes it impossible to remove the connector assembly from the transformer stud.
Additionally, it has not been possible for the industry to have a completely insulated connection to transformer studs. Standard practice which is dictatec by the insulated connector designs presently available require that the connector be threaded onto the transformer stud with a lock nut tightened against the aluminum bar connecting element. This leaves the lock nut and a portion of the transformer stud exposed. The only known method of protection is to use a shroud to cover the stud and lock nut of the transformer bushing. However, such a shroud does not provide any sealing means, but is simply designed to prevent accidental contact with the live or energized parts.
Transformers using insulated connector assemblies are those common to underground distribution. These are either surface mounted on concrete or plastic pads, or they are installed subsurface in concrete or paper composition cylinders.
Where a transformer is mounted on a surface, it is enclosed in a steel cabinet. Due to condensation, moisture is always present. In subsurface installations, the possibility of flooding is a very real one. In either type of installation, the transformer studs are normally copper while the connector must be aluminum to accomodate the aluminum cables in common use today. The juncture of the aluminum connector body and the copper transformer stud presents the components for electrogalvanic action in the presence of an electrolyte. This dictates the great need for a means of sealing the stud connection so that the entire unit is completely sealed and free from the galvanic action initiated by moisture or flooding.
An object of the present invention is to provide a positive locking action for securing a connector to a transformer bushing without damaging the threaded stud extending from the transformer bushing.
Another object of the invention is to provide a means of making a seal at the juncture of the transformer bushing stud and the insulated connector.
It is a further object of this invention to provide a positive locking means for maintaining said sealed connection in place.
These and other objects of the invention will become apparent from the following description taken in conjunction with the drawings.